The ability to rapidly and accurately process tactile patterns changing in time and space is of particular importance to sensory disabled individuals. Deaf persons use the haptic system to augment speech reading with vibrotactile aids, to interpret finger-spelling, or to translate acoustic environmental events into palpable signals. Similarly, blind persons use the sense of touch to read Braille, to read embossed maps, or to understand vibrotactile displays of text or mobility information. There have been few attempts to determine the factors that underlie the processing of tactile patterns of the type used in such displays. Similarly, the sensory, perceptual, and individual prerequisites for processing of such patterns are largely unknown. Limited research in this area has suggested that there are considerable differences among nominally homogeneous groups of individuals in tactile pattern-perception abilities. What factors might contribute to these differences? Age is one important correlate of both speech-reading skill and of vibrotactile processing speed that has been identified. This relation, combined with the fact that most auditory and visual disability is of greatest severity late in life, points up the importance of including age in any study of individual differences in tactile pattern perception. The influence of aging on several basic measures of tactile sensitivity has been examined, but changes in the ability to process patterns such as those used in vibrotactile devices have not been studied in such detail. This proposal will examine individual differences, including aging, on a number of capabilities in simple and complex vibrotactile pattern perception to determine which are predictive of ability in the processing of sequences of multidimensional, spatio-temporal vibrotactile patterns. Specifically, a number of young and older observers will be tested on several measures of (1) basic cutaneous sensitivity using single contactors and (2) elementary pattern perception using the vibrotactile displays from the Optacon, a reading machine for blind persons, and a multichannel linear array similar to some aids for speechreading. In addition, the acquisition and discrimination of abstract geometric vibrotactile patterns, presented individually and sequentially, will be tested to determine each subject's spatio-temporal pattern-processing capabilities. Data from these studies will be correlated with other individual capabilities and analyzed for factors contributing to rapid and accurate processing of pattern strings like those produced by tactile aids and displays.